Massey Ferguson 00.02.64 – Dash: Issue With Hydraulic Oil Temperature Signal Voltage (Dash)

This code indicates a malfunction in the electrical circuit for the hydraulic oil temperature sensor. Specifically, the control module is receiving an abnormal signal voltage (either too high, too low, or an open/short circuit) from the sensor, which prevents the system from accurately monitoring the hydraulic fluid temperature.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)

1. 1

   Check the hydraulic oil level and condition for signs of severe contamination, degradation, or overheating.

2. 2

   Inspect the hydraulic oil temperature sensor connector, wiring harness, and routing up to the Dash module for chafing, pinched wires, broken strands, corrosion, or fluid intrusion.

3. 3

   Backprobe the sensor signal and ground circuits with a DVOM to check for continuity and verify the 5V reference voltage.

4. 4

   Measure the sensor's resistance across its terminals at known temperatures and compare to OEM specifications (an open circuit or near 0 Ω indicates a failed sensor).

5. 5

   Perform a wiggle test on the wiring harness while observing live data or a multimeter to check for intermittent voltage drops or spikes.

1. 1

   Retrieve Data

   Read all freeze-frame and pending codes to note the exact conditions (temperature, load) when the code was set.

2. 2

   Resolve Wiring Issues

   If the visual inspection or wiggle test reveals damaged wiring or a corroded connector, repair the wiring harness or replace the pigtail connector. Ensure the ground connection to the Dash module is clean and secure.

3. 3

   Replace the Sensor

   If the wiring is intact but the sensor fails the resistance/voltage test (e.g., reads open or shorted internally), remove the old hydraulic oil temperature sensor and install a new one.

4. 4

   Fluid Maintenance

   If the hydraulic fluid was found to be low or heavily contaminated during the diagnostic phase, drain the hydraulic fluid, replace the hydraulic filter, and refill with clean, spec-compliant Massey Ferguson hydraulic fluid.

5. 5

   Clear Codes

   Clear the fault codes from the Dash module and operate the tractor to verify that the hydraulic oil temperature gauge reads smoothly and the code does not return.